Integrating Multispectral Hemodynamic Imaging for Bulk Tissue Oxygenation Analysis

Tissue perfusion and oxygenation are important factors in predicting patient outcomes, but current non-invasive devices for this type of measurement are limited to contact-based single-site monitoring. We present the co-integration of a multispectral optical-electronic subsystem into an existing non-contact coded hemodynamic imaging (CHI) device to enable image acquisition under different illuminants for spatial tissue oxygenation. Stability of the optical output for three illuminants over 10 mins was validated by the imaging system, with Ïƒmax=0.407 intensity units, reflecting stability in local fluctuations, and a maximal overall change of 3.1 units. Bulk tissue oxygenation measurement of the thenar eminence during a cuff occlusion experiment revealed relative changes in absorbance due to oxy- and deoxyhemoglobin consistent with concurrent physiological changes in chromophore concentration as described in a previous study.

Download Full-text

Comparison of the ViOptix Intra.Ox Near Infrared Tissue Spectrometer and Indocyanine Green Angiography in a Porcine Bowel Model

Journal of Reconstructive Microsurgery ◽

10.1055/s-0040-1702163 ◽

2020 ◽

Vol 36 (06) ◽

pp. 426-431

Author(s):

Nima Khavanin ◽

Hamda Almaazmi ◽

Halley Darrach ◽

Franca Kraenzlin ◽

Bashar Safar ◽

...

Keyword(s):

Indocyanine Green ◽

Indocyanine Green Angiography ◽

Near Infrared ◽

Tissue Oxygenation ◽

Imaging System ◽

Correlation Coefficients ◽

Tissue Perfusion ◽

Infrared Spectrometer ◽

Perfusion Assessment ◽

Near Infrared Spectrometer

Abstract Background This study aims to directly compare measurements of tissue oxygenation obtained using the Intra.Ox (Vioptix Inc., Fremont, CA) near infrared spectrometer with the perfusion assessment of the indocyanine green (ICG)-based SPY Elite imaging system (Stryker Co., Kalamazoo, MI) in a porcine bowel model. Methods Two live minipigs underwent laparotomy and isolation of a 30-cm segment of a large bowel. Standardized oximetry measurements were taken along the segment of bowel immediately before, after, and serially for 30 minutes following transection. A 0.5 mg/kg dose of ICG was then injected intravenously and the SPY Elite system was used to visualize and quantify tissue perfusion. Pearson's correlation coefficients were calculated using the outcomes. Results Transected and ligated bowel yielded mean Intra.Ox measurements of 61% oxygenation at the proximal base of the limb and 27.8% at the distal edges. Analysis of the relative ICG fluorescence using the SPY Elite's proprietary software yielded perfusion estimates of 64.8% proximally and 6.8% distally. Intra.Ox and SPY Elite measurements demonstrate a Pearson product–moment correlation of 0.929. Repeat measurements at 15-mm intervals along the tissue yielded decreasing Intra.Ox measurements along the length of the flap that correlate to SPY Elite measurements (r = 0.645). Conclusion Both the Intra.Ox and the SPY detected clinically relevant changes in bowel oxygenation following transection and ligation. The use of intravenous ICG dye did not appear to affect measurements of tissue oxygenation obtained using the Intra.Ox.

Download Full-text

Evaluating Changes in Regional Tissue Perfusion Following Percutaneous Lower Extremity Revascularization Procedures With a Hyperspectral Image-Based Tissue Oxygenation Mapping System

Journal of Vascular Surgery ◽

10.1016/j.jvs.2011.06.070 ◽

2011 ◽

Vol 54 (3) ◽

pp. 925

Author(s):

Dipankar Mukherjee

Keyword(s):

Lower Extremity ◽

Tissue Oxygenation ◽

Hyperspectral Image ◽

Tissue Perfusion ◽

Mapping System ◽

Revascularization Procedures ◽

Lower Extremity Revascularization

Download Full-text

Carbon dioxide and tissue oxygenation: is there sufficient evidence to support application of hypercapnia for hemodynamic stability and better tissue perfusion in sepsis?

Intensive Care Medicine ◽

10.1007/s00134-008-1184-7 ◽

2008 ◽

Vol 34 (10) ◽

pp. 1752-1754 ◽

Cited By ~ 8

Author(s):

Ozan Akça

Keyword(s):

Carbon Dioxide ◽

Tissue Oxygenation ◽

Tissue Perfusion ◽

Sufficient Evidence ◽

Hemodynamic Stability

Download Full-text

Retinal functional imager (RFI): Non-invasive functional imaging of the retina

Nepalese Journal of Ophthalmology ◽

10.3126/nepjoph.v5i2.8738 ◽

2013 ◽

Vol 5 (2) ◽

pp. 250-257 ◽

Cited By ~ 8

Author(s):

Sunil Ganekal

Keyword(s):

Functional Imaging ◽

Structural Changes ◽

Imaging System ◽

Retinal Blood Flow ◽

Capillary Perfusion ◽

Functional Changes ◽

Non Invasive ◽

Retinal Disorders ◽

Retinal Blood Flow Velocity ◽

Perfusion Maps

Retinal functional imager (RFI) is a unique non-invasive functional imaging system with novel capabilities for visualizing the retina. The objective of this review was to show the utility of non-invasive functional imaging in various disorders. Electronic literature search was carried out using the websites www.pubmed.gov and www.google.com. The search words were retinal functional imager and non-invasive retinal imaging used in combination. The articles published or translated into English were studied. The RFI directly measures hemodynamic parameters such as retinal blood-flow velocity, oximetric state, metabolic responses to photic activation and generates capillary perfusion maps (CPM) that provides retinal vasculature detail similar to flourescein angiography. All of these parameters stand in a direct relationship to the function and therefore the health of the retina, and are known to be degraded in the course of retinal diseases. Detecting changes in retinal function aid early diagnosis and treatment as functional changes often precede structural changes in many retinal disorders. Nepal J Ophthalmol 2013; 5(10): 250-257 DOI: http://dx.doi.org/10.3126/nepjoph.v5i2.8738

Download Full-text

Measurement of Peripheral Venous Oxygen Saturation in the Leg Using Near-Infrared Spectroscopy

Phlebology The Journal of Venous Disease ◽

10.1177/026835559701200305 ◽

1997 ◽

Vol 12 (3) ◽

pp. 96-99 ◽

Cited By ~ 2

Author(s):

D. Wertheim ◽

R. Salaman ◽

J. Melhuish ◽

R. Williams ◽

I. Lane ◽

...

Keyword(s):

Near Infrared ◽

Tissue Oxygenation ◽

Venous Occlusion ◽

Lower Leg ◽

Non Invasive ◽

Short Period ◽

Venous Oxygen Saturation ◽

Invasive Method ◽

Healing Of Wounds ◽

Total Haemoglobin

Background: It has been suggested that poor healing of wounds may be associated with reduced tissue oxygenation. A non-invasive method of assessing peripheral venous oxygenation has been investigated. Method: Changes in oxyhaemoglobin (O2Hb), deoxyhaemoglobin (HHb), oxidized cytochrome aa3 (cyt aa3) and total haemoglobin (tHb) were monitored in the left lower leg of seven healthy volunteers. A short period of venous occlusion was achieved by rapidly inflating a sphygmomanometer cuff placed around the leg to 60 mmHg. The changes in O2Hb and tHb, with respect to the baseline readings, were evaluated. PSvO2 was calculated from (ΔO2Hb/ΔtHb) × 100%. Results: From 17 sets of readings on the seven volunteers the median PSvO2 calculated was 64% (range 50–86%). Conclusion: This method appears to be a simple means of evaluating PSvO2. A change in cyt aa3 was often seen associated with the venous occlusion.

Download Full-text

PS01.168: IS IT POSSIBLE TO PREVENT GASTRIC TUBE NECROSIS FOLLOWING ESOPHAGECTOMY?

Diseases of the Esophagus ◽

10.1093/dote/doy089.ps01.168 ◽

2018 ◽

Vol 31 (Supplement_1) ◽

pp. 97-97

Author(s):

Katsunori Nishikawa ◽

Yujiro Tanaka ◽

Yuichiro Tanishima ◽

Shunsuke Akimoto ◽

Fumiaki Yano ◽

...

Keyword(s):

Gastric Tube ◽

Assessment Tool ◽

Imaging System ◽

Conflicts Of Interest ◽

Tissue Perfusion ◽

Early Postoperative Period ◽

Partial Replacement ◽

Full Thickness ◽

Intraoperative Assessment ◽

Vascular Insufficiency

Abstract Background Gastric tube necrosis (GN) following esophagectomy is a rare, but critical and life threatening complication. Unlike anastomotic leakage due to local ischemia, GN involves extensive full thickness ischemia resulting from vascular insufficiency. Most cases of GN need total or partial replacement of gastric tube. Although quantitative assessment of tissue perfusion during esophageal surgery contributed to reduce the incidence of postoperative anastomotic complications, GN remains a serious complication to be solved. Methods Data were collected retrospectively from 271 patients who underwent esophagectomy and gastric tube reconstruction at a single center between 2008 and 2018, in which cases of GN were identified. Gastric mobilization was mainly performed laparoscopically using a hand-assisted maneuver. The short gastric and left gastric arteries were divided, and the right gastric and gastroepiploic arteries were both preserved. The gastric tube 3.5 cm in width was created along the greater curvature. Intraoperative assessment of perfusion of the gastric tube was performed using our novel Thermal Imaging System (TIS) in all patients. Quantitative tissue perfusion scores defined as anastomotic viability index (AVI) were calculated at various points from the anastomosis. Results The inpatient mortality rate was 1.8% (n = 5). Anastomotic leak (AL) developed in 8.8% (n = 24) of the study group. The mean AVI score of cases with AL was 0.58, which was significantly lower than that without AL (0.71, P < 0.001). GN occurred in two patients (0.7%). The AVI score of the both GN cases were relatively high at 0.74 and 0.82. In one of the cases, circumferential full thickness ischemia 10 cm in length from the esophagogastric anastomosis was revealed by contrast CT scans and endoscopy, which was later identified to be due to severe vascular impairment. Conclusion TIS can be used as a reliable intraoperative assessment tool for perfusion of the gastric tube. We assume that most AL would be caused by delayed anastomotic healing due to poor vascularization of the gastric tube. On the other hand, obvious difference in AVI scores between AL and GN may indicate the involvement of different etiology. Given that development of GN seemed to be caused by acute failure in vascularization during the early postoperative period. Disclosure All authors have declared no conflicts of interest.

Download Full-text

Advances in the Application of the Dual Fluoroscopic Imaging System in Sports Medicine: A Literature Review

Journal of Medical Imaging and Health Informatics ◽

10.1166/jmihi.2021.3579 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2067-2076

Author(s):

Cui Zhang ◽

Xiaole Sun ◽

Yunqi Tang ◽

Shaobai Wang ◽

Dongqiang Ye ◽

...

Keyword(s):

Sports Medicine ◽

Soft Tissues ◽

Imaging System ◽

Relevant Literature ◽

Test Results ◽

Non Invasive ◽

Ligament Strain ◽

Fluoroscopic Imaging ◽

Analysis System ◽

Six Degree Of Freedom

The dual fluoroscopic imaging system (DFIS) is a new non-invasive motion analysis system that does not interfere with movement, has high precision and repeatability and is not affected by the errors caused by the relative movement of skin and soft tissues. DFIS has been recently used in the field of sports medicine. This narrative review focuses on relevant literature on the origin, development and mechanism of action of DFIS and summarises the application of DFIS in injury and rehabilitation treatment, such as the reliability of test results; the position relationships of bony structures in the shoulder, lumbar spine, knee joint and ankle joint during exercise and its six degree-of-freedom (6DOF) movement to calculate cartilage deformation, contact area/trajectory and ligament strain. This article puts forward the problems encountered in practice that need to be solved and looks forward to the future applications of DFIS in the field of sports, especially in injury prevention and treatment.

Download Full-text